1. Field of the Invention
The present invention relates to an ink jet recording apparatus.
2. Related Background Art
Conventionally, there are ink jet recording apparatuses comprising recovery units for removing wet ink on the surface having an array of discharge ports caused by the ink mist occurring in discharging the ink from recording head, or the satellite ink occurring in refilling the ink, and the suction residual ink occurring in the recovery process such as the suction. This recovery apparatus is mainly comprised of a suction unit, for example, for forcing the ink to be discharged from the discharge port, and a wiping unit for wiping and cleaning the discharge port array face. In order to make the wiping (or cleaning) of the discharge port array face (hereinafter referred to as a discharge face) for an ink jet recording head having a plurality of discharge ports, for example, the wiping unit is constituted so as to wipe, in a scraping manner, the discharge port array face with a blade made of an elastic material placed directly against the discharge face while moving the blade relative to the ink jet recording head, to thereby clean the discharge port and its surrounding to maintain the stability of discharging.
Here, taking an example of ink deposition on the discharge face which may appear with the suction recovery, a conventional cleaning operation will be described with reference to FIG. 29.
A carriage 902 having an ink jet recording head 901 is carried on a main scan rail 903, and attached movably in a print direction (direction of arrow C). If the discharge port of the ink jet recording head 901 may be clogged, a holder 905 having gum caps 904 forming a closed system for the head is moved in a direction of arrow a by driving means, not shown, so that the gum caps 904 are brought into contact with the discharge face 901a of the ink jet recording head 901 and stopped at a position where the closed system is created. In this state, the suction recovery is performed via tubes 906 with a suction pump 907. The ink pulled out from the ink jet recording head 901 due to the suction is transported via a tube 908 into a waste ink processing member 909. After the suction recovery, the holder 905 having the gum caps 904 are retracted in the direction of arrow b by the driving means. At this time, ink droplets I pulled out from nozzles may remain on the discharge port 901a of the ink jet recording head 901. The carriage 902 having the ink jet recording head 901 is moved in the direction of arrow C [(A) state], the wiping for the discharge port 901a is performed with a gum blade 910 carried by a blade holder 911 [(B) state], whereby ink droplets I on the discharge face 901 are removed from the discharge face 901a. 
However, to improve the cleaning performance for the discharge face of ink jet recording apparatus and stabilize the discharge characteristics in a long term service, there are conventionally the following problems, particularly in a color recording apparatus having a cartridge-type head or a plurality of heads.
The first problem is that the ink accumulating in a gap between the head and the carriage may cause an adverse effect.
That is, there is a fear that in wiping ink droplets remaining on the discharge face of head after the print or suction, the ink enter the gap between the head and the carriage, as shown in the (B) state of FIG. 29, and the accumulating ink may drip after a long term of service or scatter away due to the engagement with the blade, thereby polluting a print face or back face of print sheet. Also, there is a further fear that when the accumulating ink contains dust or thickens, it be retransferred onto the blade in cleaning to enter the discharge ports of the head downstream in the wiping direction, thereby causing a print deflection or undischarge. Further, the undischarge owing to intermixed dust or thickened ink may exert the adverse effect on energy generating elements for use in discharging the ink (e.g., scorching of heat generating element).
Second, there is a problem of the adverse effect due to the swept ink in wiping.
That is, most recent ink jet recording heads have a plurality of discharge ports arranged, so that the wiping is carried out with a wider blade than a discharge port array range. However, a considerably greater amount of ink droplets may remain if the number of discharge ports increases, and this ink tends to remain on the discharge port array facing downstream of the blade in the wiping direction. If ink droplets remaining on this portion may be fixed in a long term service, an failure of enclosing a cap portion may occur. If this occurs, the print deflection or undischarge is likely to occur due to capping failure with the non-used recording head, and further a failure of suction or wiping may arise.
Further, thirdly, with the apparatus having a plurality of heads corresponding to the inks differing in the color tone, if the wiping is made for such heads in sequence, there is a fear that the adhering ink (wet ink) to the discharge face in the vicinity of discharge ports of the head upstream of the wiping may be transferred onto the blade in wiping after the ink suction or print, and the inks different in the color may enter discharge ports of the head downstream thereof. Thus, the color mixture of different ink colors or the undischarge failure due to the mixture of different components may occur.
Further, fourthly, there is a problem associated with the exchange of a cartridge type head. That is, when the cartridge type head is exchanged, the operator may dirty his hands or clothes with the exchange of the head if the head is polluted with the adhering ink for the above reason.
On the other hand, in order to make the recording at high precision or with high quality, it is required to reduce the dispersion between product heads as least as possible. To meet this requirement, a method has been proposed in which data concerning the uneven density for each head is measured in fabricating the ink jet head, and the correction data for correcting the driving condition of head or various characteristics for the image processing are prewritten into a semiconductor memory (e.g., ROM) which is mounted on the product, thereby controlling the discharge and reducing the negative effects caused by the previous problem.
Though the cleaning of discharge ports is an important factor for improving the recording quality in the ink jet recording as previously described, the wiped out ink may be scattered away with the restoring force of a cleaning blade due to its elasticity which may be separated from discharge port formation face, in cleaning the discharge port formation face with the wiping of the cleaning blade. Thus, there is a fear that the apparatus may be internally polluted with such scattered ink, or the ink may flow around the side face of head, and stick to the memory device provided on the head, causing a malfunction or breakdown.
It is an object of the present invention to provide recording means which can resolve those problems and attain a high quality of recording, and an ink jet recording apparatus with said recording means mounted thereon.
In order to resolve the aforementioned problems, the present invention provides an absorbing member for wiping out the ink adhering to a cleaning blade between recording heads. In particular, the absorbing member is disposed between each recording head to clean the blade while at the same time cleaning the discharge port face of recording head. Also, the absorbing member between recording heads may be mounted on the side face of recording head, or on the portion between each recording head mounting unit of a carriage for mounting the recording head.
The present invention has been proposed to accomplish the aforementioned objects, in which a view has been obtained that an ink permeation preventing member provided in the neighborhood of the discharge port formation face and on the side face of head can offer the favorable effect in order to clean excellently a discharge port formation face of recording head without the occurrence of the ink sticking to a semiconductor memory or the ink mist flying within the apparatus.
On the basis of such a view, the present invention provides recording means having integrally a recording head unit having discharge ports for discharging the ink and ink channels communicating to said discharge ports and leading the ink thereto, and an ink tank unit for storing the ink to be supplied to the recording head unit, characterized in that said recording head unit comprises a device for storing the parameter information concerning the ink discharge characteristics, and a protective member disposed on a side face area adjacent to said discharge port formation face for preventing the ink from flowing around.
Also, there is provided recording means having integrally a recording head unit having a device for storing the parameter information concerning the ink discharge characteristics, as well as having discharge ports for discharging the ink and ink channels communicating to said discharge ports and leading the ink thereto, and a protective member disposed on the area adjacent to said discharge port formation face for preventing the ink from flowing around, and an ink tank unit for storing the ink to be supplied to the recording head unit, characterized by comprising a recording head cartridge mounted on the apparatus so as to be freely detachable therefrom, a support member having an electrical connecting portion for passing a recording signal to said recording head cartridge mounted, and a cleaning member disposed on a region out of the recording area with said recording head cartridge for cleaning said discharge port formation face while being in direct contact with said discharge port formation face.
With such a constitution, it is possible to provide highly reliable recording means capable of attaining a high quality of recording, and an ink jet recording apparatus with the recording means mounted, while preventing the ink mist from scattering within the apparatus, as well as preventing the flying ink from sticking to a semiconductor memory or electrical contact point mounted on an ink head cartridge.
Also, the present invention has been proposed to accomplish the aforementioned objects, in which a view has been obtained that the adhering ink on the blade can be wiped out more surely by setting a blade cleaning mode. On the basis of this view, the present invention provides an ink jet recording apparatus having a cleaning member for cleaning a discharge port face of a recording head for recording with the discharge of the ink, characterized by comprising a cleansing member for cleansing said cleaning member while being in contact with said cleaning member, and means for setting a first cleaning mode of cleaning said discharge port face and a second cleaning mode of cleansing said cleaning member with said cleansing member.
That is, porous absorbing members are provided on a carriage having recording heads mounted thereon, particularly, on the portion before and after a recording head in the cleaning direction, so that the ink transferred to the blade in wiping a previous recording head is absorbed into its absorbing member not to cause any trouble such as residual ink or mixed color to occur in the recording head to be wiped next, and further a blade cleaning mode switch is provided or a blade dedicated cleaning mode is set so that the blade cleaning mode may be made effective for every predetermined number of sheets.
This blade cleaning mode is one in which the penetrating amount of the blade is set to be deeper than at the ordinary wiping, and the cleaning is performed for a wider range than that placed into contact with the blade at the wiping of predetermined intervals, in a single direction or both directions by a predetermined number. With such blade cleaning mode, it is possible to remove residual ink on the blade more fully, which can not be absorbed into the absorbing member at the normal wiping, and accomplish a more reliable wiping.
Further, the present invention provides an ink jet recording apparatus for recording with the discharge of the ink onto a recording medium, characterized by comprising a wiping member for wiping by engaging a face of said recording head provided with said discharge ports each having a shape not to be in line symmetry about a predetermined axis, and wiping direction defining means for defining the wiping direction so that said wiping member may make the wiping from shorter to longer side of two discharge port peripheral length components lying on both sides of said predetermined axis with respect to a line segment having the maximum length with which said predetermined axis is intercepted by a contour line of said discharge port.
Here, the predetermined axis is taken as an axis perpendicular to said wiping direction.
The discharge port may be shaped as a polygon, or a polygon having rounded corners.
When the discharge port is shaped as a trapezoid having an upper base and a lower base parallel to said predetermined axis, the line segment of the maximum length is equal to the lower base, so that the shorter discharge port peripheral length component is the lower base, and the longer discharge port peripheral length component is the upper base plus two oblique lines.
On the other hand, the present invention provides a recording head having discharge ports for the discharge of the ink onto a recording medium, each discharge port being of a shape not in line symmetry about a predetermined axis, characterized in that the face of the recording head having said discharge ports is wiped by engagement with the wiping member from shorter to longer side of two discharge port peripheral length components lying on both sides of said predetermined axis with respect to a line segment having the maximum length with which said predetermined axis is intercepted by a contour line of said discharge port.
According to the present invention, owing to the ability of determining the wiping direction suitable for the shape of a discharge port, an ink jet recording head provided with discharge ports each having a complex shape or special shape in consideration of the stabilization of discharge characteristics, and liquid channels, makes it possible to prevent dust or thickened ink from returning inward to the discharge ports with the wiping, as well as reducing the pulling out of the ink from the discharge ports in wiping and the color mixture in wiping a plurality of heads, so that the image quality can be stably maintained, with reduced recording deflection or undischarge, by realizing the stabilization in the discharge characteristics of the head as well as the improvement of the reliability. In particular, when the discharge port is formed as a polygon (or a polygon having rounded corners), there is a great effect in wiping the ink jet recording head.
Further, the present invention is aimed to resolve the above-mentioned problems, and comprises a discharge portion for discharging the ink to a recording medium, characterized in that an end face of said absorbing member is convex relative to an end face of said discharge portion, and/or the end face of said discharge portion adjacent to said absorbing member is concave relative to the end face of said absorbing member.
Also, an ink jet head cartridge of the present invention is characterized in that an ink jet recording head has integrally an ink tank for storing the ink to be supplied to said head.
Also, an ink jet recording apparatus of the present invention is characterized by comprising a recording head, a mounting member for mounting said recording head, a wiping member engageable with an end face of said discharge portion and an end face of said absorbing member, and wiping direction defining means for defining the wiping direction so that said wiping member may engage the end face of said absorbing member after engaging the end face of said discharge portion.
Further, an ink jet recording apparatus of the present invention is characterized by comprising a recording head having a discharge portion for discharging the ink to a recording medium and a first absorbing member provided in the vicinity of said discharge portion, a mounting member for mounting said recording head, a second absorbing member provided on said mounting member adjacent to and in the vicinity of the first absorbing member, a wiping member engageable with said discharge portion, said first absorbing member and said second absorbing member, and wiping direction defining means for defining the wiping direction so that said wiping member may engage said first absorbing member after engaging said discharge portion, and then said second absorbing member.
The discharge portion has means for generating the heat energy to cause the film boiling in the ink as the energy useful for discharging the ink.
The recording head is in the form of a head cartridge having integrally an ink tank for storing the ink to be supplied to said discharge portion.
Further, said mounting member can mount a plurality of recording heads, each of which is mounted so that said absorbing member is disposed in the same direction, or said second absorbing member is disposed downstream of each of said recording heads in the wiping direction.
Here, said plurality of recording heads can be provided corresponding to the inks different in the color tone.
Further, a cleaning method of the present invention is characterized in that for a recording head having a discharge portion for discharging the ink to a recording member and a first absorbing member provided in the vicinity of said discharge portion, after the cleaning with said wiping member engaging said discharge portion, said wiping member is caused to engage said first absorbing member, and then said second absorbing member provided on a mounting member for said recording head to be adjacent to said first absorbing member.
Here, said wiping member can be used in the continuous operation for a plurality of recording heads and a plurality of second absorbing members.
According to the present invention, it is possible to clean the wiping member in such a manner as to cause the wiping member to engage an absorbing member disposed in the vicinity of the discharge portion of recording head, after wiping the discharge portion, or an absorbing member provided on a head mount such as carriage. Also, it is possible to perform the absorbing operation of the ink more securely by making the absorbing member on the head side convex, and/or the end face on the discharge portion concave.
Accordingly, as impurities having the adverse effect on the head such as dust or thickened or fixed ink adhering to the wiping member or cap can be removed beforehand, and efficiently, an excellent effect can be exhibited against conventional troubles such as a trouble of the ink accumulating in the gap between head and carriage, a trouble of the ink swept in wiping, the color mixture in wiping a plurality of heads, or the pollution of the operator in exchanging the cartridge head, with an improved durability and print characteristic.
Also, the present invention is provided with a discharge portion for discharging the ink to a recording member and an absorbing member provided in the vicinity of said discharge portion, characterized in that assuming that the ink capacity of ink tank for storing the ink to be supplied to said discharge portion is I[g], and the volume of said absorbing member is A[cm1], the relation of {fraction (1/15000)} less than A/I less than ⅕ stands.
Here, assuming that the weight of ink to be usable for recording among the ink stored within said ink tank is L*[g], the relation of {fraction (1/12500)} A/I* less than {fraction (3/10)} stands.
Also, said absorbing member can be made of a material having a swelling rate of 0.02% or less in absorbing the liquid.
Further, said absorbing member can be made of a material having a liquid absorbing rate of 30% to 60%.
Further, an ink jet recording apparatus of the present invention is characterized by comprising a recording head having a discharge portion for discharging the ink to a recording medium and an absorbing member provided in the vicinity of said discharge portion, a mounting member for mounting said recording head, a wiping member engageable with said discharge portion and said absorbing member, and wiping direction defining means for defining the wiping direction so that said wiping member may engage said absorbing member after engaging said discharge portion.
In addition, a cleaning method of recording head according to the present invention is characterized in that for a recording head having a discharge portion for discharging the ink to a recording member and an absorbing member provided in the vicinity of said discharge portion, after cleaning with said wiping member engaging said discharge portion, said wiping member is caused to engage said absorbing member.
Here, said wiping member can be used in the continuous operation for a plurality of recording heads.
According to the present invention, it is possible to clean the wiping member in such a manner as to cause the wiping member to engage the absorbing member after wiping of the discharge portion, with the absorbing member provided adjacent to the discharge portion of recording head.
Accordingly, as impurities having the adverse effect on the head such as dust or thickened or fixed ink adhering to the wiping member or cap can be removed beforehand, and efficiently, an excellent effect can be exhibited against conventional troubles such as a trouble of the ink accumulating in the gap between head and carriage, a trouble of the ink swept in wiping, the color mixture in wiping a plurality of heads, or the pollution of the operator in exchanging the cartridge head, with an improved durability and print characteristic.
Further, according to the present invention, it is possible to derive the optimum condition on the constitution for the absorbing member in the respect of size, function and cost, by making clear the swelling rate and the liquid absorbing rate of absorbing member provided on the head, as well as the relation between the ink weight within the ink tank, the recordable ink weight, and the size of absorbing member.
The present invention has been achieved in the light of the above-mentioned problems, and comprises a recording head having a discharge portion for discharging the ink to a recording medium and an absorbing member provided in the vicinity of said discharge portion, and a wiping member engageable with said discharge portion and said absorbing member, characterized in that the following relation can stand, the range of discharge port array  less than  the width of wiping member xe2x89xa6 the width of absorbing member.
Further, there is provided a mounting member for mounting the head, wherein said member can mount a plurality of recording heads, each of which is mounted so that said first absorbing member is disposed in the same direction, or said second absorbing member is disposed downstream of each of said recording heads in the wiping direction.
Here, said plurality of recording heads can be provided corresponding to the inks different in the color tone.
According to the present invention, it is possible to cleanse the wiping member more surely in such a manner that with the appropriate dimensions, an absorbing member is disposed in the vicinity of the discharge portion for the recording head, and the wiping member is caused to engage the absorbing member after wiping the discharge portion, and further engage an absorbing member provided on the head mount such as carriage.
Accordingly, as impurities having the adverse effect on the head such as dust or thickened or fixed ink adhering to the wiping member or cap can be removed beforehand, and efficiently, an excellent effect can be exhibited against conventional troubles such as a trouble of the ink accumulating in the gap between head and carriage, a trouble of the ink swept in wiping, the color mixture in wiping a plurality of heads, the pollution of the operator in exchanging the cartridge head, with an improved durability and print characteristic.